Excited States of the divacancy in SiC

The divacancy in SiC - a technologically mature material that fulfills the necessary requirements\footnote{J.~R.~Weber \emph{et al.}, PNAS \textbf{107}, 8513 (2010).} for hosting defect based quantum computing - is a good candidate for implementing a solid state quantum bit. Its ground state is isovalent to the NV center in diamond as demonstrated by density functional theory (DFT).\footnote{A.~Gali, phys. status solidi (b) \textbf{248}, 1337 (2011); J.~P. Gross \emph{et al.} \textbf{77}, 3041 (1996).} Furthermore, coherent manipulation of divacancy spins in SiC has been demonstrated.\footnote{F.~Koehl \emph{et al.}, Nature\textbf{479}, 84 (2011).} The similarities to NV might indicate that the same inter system crossing (ICS) from the high to the low spin state is responsible for its spin-dependent fluorescent signal. By DFT and a DFT-based multi-reference hamiltonian we analyze the excited state spectrum of the defects. In contrast to the current picture of the spin dynamics of the NV center, we predict that a static Jahn-Teller effect in the first excited triplet states governs an ICS both with the excited and ground state of the divacancy.